Fire control mechanism



April 24, 1951 l A. F. GAlDos 2,549,797

FIRE CONTROL MECHANISM Filed June 2l, 1946 2 Sheets-Sheet 1 :Ej g l /fff 4 mw #l J5 28 I7/ ALnnz 1:1 F. E adnS @www April 24, 1951 A. F. GAlDos FIRE CONTROL MECHANISM 2 Sheets-Sheet 2 Filed June 2l, 1946 3mm/rm, Alm-LZ 1:1 'Fl EadmS Patented Apr. 24, 1951 UNITED STATES TENT OFFICE (Granted under the act of MarchV 3, 1883, as amended April 30, 1928; 370 OsG. 757) 4 Claims.

The invention described herein may be manufactured and used by or for the Goverment for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a fire controlv mechanism and more particularly to a re control mechanism for obtaining semi-automatic fire in a firearm.

It is an object of this invention to provide a re control mechanism for an automatic firearm to obtain semi-automatic re wherein the hammer of such mechanism is automatically cocked by the opening stroke ofthe reciprocating breech member of the firearm and wherein the trigger must be pulled each time for release of the hammer.

A particular object of this invention is to provide a semi-automatic fire control mechanism having a siidable trigger for effecting release of the hammer.

Another object of this invention is to provide a semi-automatic re control mechanism for a firearm wherein the hammer and sear mechanism is contained in a unit separable from another unit containing a sliding trigger and disconnector whereby positive inspection and adjustment of the parts may be more readily effected. Y

The speci-lic nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred'e'mbodiment as shown in the accompanying drawings in which:

Figure 1 a fragmentary longitudinal sectional view of the triggerv mechanism assembled in a rearm, the parts thereof being in armed position;

Figure 2 is a similar view showing the partsin fired position;V

Figure 3 is an` exploded perspective view of the trigger housing; and

Figure 4 is a similar view showing the trigger mechanism.

This invention provides a novel re control mechanism to effect semi-automaticfunctioning of a firearm by utilizing'a sliding' trigger andv a disconnector to effect release ofa sear Whensuch trigger is pulled rearwardly. Such disconnector is positively disconnected from the sear after such sear has been released inY order to permit the sear to re"engage ther scar notchin the harnmer as such hammer is re-cock'ed' in order to provide semi-automatic r'e. Thus more than one cartridge cannot be discharged' with but a single pull of the trigger because such trigger must be released and allowed to travel to its forward position before a succeeding cartridge can be fired.

In Figure 1 there is shown in assembled relation a preferred embodiment of this invention. The elements of the trigger mechanism shown in such gure are mounted in a trigger housing I and such housing is contained within a, firearm 50 and suitably secured thereto. To facilitate manufacture, trigger housing I preferably comprises tWo parts. An upper part 2 of trigger housing I is slidably connected to trigger housing I by cooperation of a T-shaped rib 3 provided on top of trigger housing I with a corresponding way 4 in the base of upper part 2. Upper part 2 may be rigidly secured to housing I by any convenient means such as by a screw 5I, Welding or staking. A trigger 5 is slidably mounted in trigger housing I while a hammer 6 and a sear 'I are pivotally mounted on the upper part 2 as will be presently described.

A horizontal recess 8 is provided on top of trigger housing I as shown in Figure 1 wherein trigger 5 is mounted to have a smooth sliding fit therein limiting said trigger to fore and aft translation. A substantially rectangular portion 9y is provided onl top of trigger 5 which rests within recess 8. A horizontal hole I0 is provided in trigger housing I in the rear of recess 8 as shown in Figures 1 and 3. A spring biased plunger II is insertedv in lsuch hole and plunger II bears against the rear Surface of an upstanding projection 5a of t1igger'5 to bias such trigger forwardly. See Figure 4. A disconnector I3 is pivotally mounted by a horizontal transverse' pin I4 mounted in holes in upstanding lugs 5b and `5c of trigger 5.

Disconnector I3 is a substantially rectangular member and is provided with a horizontal rearwardly projecting lug I6 on its rear end which is engaged by a vertical spring I1 mounted in a vertical hole I8 provided in the rear end of trigger as clearly shown upon Figure 4. The forwardly projecting end 2D of disconnector I3 rests on the top of a shelf I9 provided on the forward end of trigger 5. Spring Il is provided to bias disconnector I 3 toward clockwise rotation to bear against sear 'I as will be later described'.

A safety 2| is mounted in trigger housing I in back of trigger 5 as shown in Figure 1 'in a transverse hole 22. Safety 2I is constructed and mounted to selectively block the rearward travel of trigger 5 to prevent release of sear 1 from hammer 6. The blocking trigger 5 is accomplished by engagement of an integral, rearwardly of spring 39a.

3 projecting lug 23 on the trigger with safety 2|' when in its safe position, thereby obstructing rearward travel of trigger 5.

Safety 2| is provided with a slot 24 in the center thereof. When safety 2l is pushed transversely across trigger guard housing I to bring slot 24 into alignment with lug 23, trigger 5 is then Vfree to be pulled rearwardly without interference from the safety. Safety 2l is yieldingly held in either of its two positions by a suitable detent VV(not shown).

A vertical slot 25 is provided in the upper part 2 of trigger housing I and hammer 5 is pivctally mounted in such slot by a transverse pin 25, mounted in holes 26a in part 2. Hammer 5 is of conventional configuration. A sear notch 21 provided on the lower end of such hammer is engaged by the sear I when hammer 6 is in the cocked position as shown in Figure l. An integral lug 23 is provided on the forward edge of hammer E which strikes a shelf 29 on the forward end of upper part 2 of trigger housing l. Thus a stop is provided for hammer t which restrains such hammer from forwardly rotating substantially beyond its normal red position when the mechanism is not assembled to a firearm. v Y

A recess 3i! is provided in the rear surface hammer 6 which provides a seat for a head 3l attached to the forward end of a strut 32. One

-endof said strut projects rearwardly through an opening 35 provided in an upstanding lug 3d on the rear end of part 2. A spring surrounds the strut 32, one end of which abuts the lug and the other against .head 3i, and provides pressure to hold the strut against the hammer. The rear end of opening 35 is counterbored as shown in Figure 1 to provide freedom of movement of strut 32 as hammer 5 pivots about pin 26.

Sear l is pivotally mounted on a transverse pin 36 back of hammer 64 as shown in Figure l. This pin is mounted-in holes 36a in upper part 2. See Figure 3. VSear 'l comprises two angularly-related arms 3'! and B8. The end of arm 3l is shaped to engage sear notch 2l of hammer' 6. The end of arm 38 is of suitable shape to engage notch I of disconnector I3 when the trigger-is in forwardvposition. A spring biased plungerl' horizontally mounted in a suitable bore in the upper part 2 of trigger housing i biases'sear I in a counterclockwise direction as shown in Figure l so that arm 3l will continu ally bear against the bottom of hammer' The sear mechanism above described becomes operative when hammer 23 has been rotated to the cocked position shown in vFigure 1. Such cooking of hammer S is normally effected by rearward movement of the reciprocating breech member iii of the rearm 5i) to which this trigger mechanism may be assembled. When hammer Ei has been rotated to the position shown in Figure l, arm 31 of sear a snaps into engagement withI sear notch 2 of hammer t. The end of arm 38 of sear I is likewise in engagementV with notch I5 provided on disconnector I3 when the hammer is in cocked position. Trigger 5 is then in a forward position so that the front end thereof will bear against the front end of recess 8.

To release'hammer 6, trigger 5 is pulled rearwardly to the position sho-wn in Figure 2. trigger 5 Vslides rearwardly, sear l is rotated in a clockwise direction against the compression This forces the end of arm El of sear 'I to slip out of sear notch 2l in hammer 5 position by pressure of the nger. Ying breech member 4i! of firearm 59 then strikes thereby permitting hammer 6 to rotate forwardly under the bias of spring 33. The end of arm 38 of sear 'I is raised sufhciently so that such end will clear the notch I5 and spring biased plunger 39 will urge sear l in a counterclockwise direction so that the end of arm 31 of scar l will bear against the bottom of hammer 6. An arcuate clearance surface 52 is provided on top of disconnector I3 to permit the end of arm 38 of sear 'l to freely rotatein a counterclockwise direction about pin 35 and thereby keep the end of arm 3l in contact with hammer 6 when trigger 5 is pulled rearwardly a sufcient distance to trip the sear and release the hammer.

Trigger 5 is now held rearwardly in the fired The recoilhammer and rotates such hammer rearwardly whereupon the end of arm 31 of sear 'I is rotated counterclockwise into sear notch 21 by the spring biased plunger- 39. Thushammer 6 is held in the cocked position and cannot be released until trigger 5 to go forwardly. Spring biased plunger l l forces trigger 5 forwardly when the linger is removed from trigger 5. As such trigger goes forwardly, disconnector E3 is forced to pivot in a counterclockwise direction against the bias of spring I'I as suchdisconnector and trigger pass underneath the end of arm 33 of sear l. When trigger 5 has reached the forward limit of travel, disconnector lt slips over the end of arm 353 of Sear 'l and snaps upwardly under urge of spring II into engagement with the forward face such arm so that arm will be in engagement with notch i5. Hammer 6 may now be released by another pull of trigger 5 which releases the sear in the same manner as above described.

It should be noted that by proportioning the length of the Sear arm 33 relative to arm 3l', the

frictional resistance exerted bythe hammer on the sear during the releasing movement of the soar may be greatly diminished so far as its effect on trigger pull is concerned.

From the foregoing description it is apparent that a -simple and positive semi-automatic re control mechanism is hereby provided. It is further evident that such mechanism can be readily adapted to any firearm utilizing a reciprocating bolt member to effect rotation of the hammer for cooking purposes.

I claim:

1. A fire control mechanism for a iirearm comprising a first and second housing separably mounted thereto, a hammer pivotally mounted in said first housing, a sear pivotally mounted in said first housing, said sear being engageable with said'hammer to retain said hammer in a cocked position, a trigger slidably mounted in said second housing for longitudinal movement relative to said sear, and a disconnector on said trigger engageable with said sear during rearward movement of said trigger to pivot said sear out of engagement with said hammer.

2. The combination dened in claim 1 wherein said disconnector comprises a member pivotally mounted on said trigger, a spring biasing said disconnector into a sear engaging position, said disconnector being constructed and arranged relative to said sear to disengage therefrom after movement of said Sear to its hammer releasing position, and a'second spring biasing said sear to its hammer engaging position overlying said dis'- connector in the pulled position of the trigger.

3.v A fire control mechanism for a firearm comis released and permitted v man.

prising a rst and second housing, means for slidably connecting said rst and second housings, a mammer pivotally mounted in said first housing, a sear pivotally mounted in said rst housing, said sear being engageable With said hammer to retain said hammer in a cocked position, a trigger slidably mounted in said second housing for longitudinal movement relative to said sear, and a disconnector on said trigger engageable with said sear during rearward movement of said trigger to pivot said sear out of engagement with said hammer.

4. A re control mechanism for a rearm comprising a rst and second housing, means for slidably connecting said first and second housings, a hammer pivotally mounted in said first housing, spring means urging said hammer from a cocked position to a ring position, a sear pivotally mounted on said first housing, said sear being engageable with said hammer to retain said hammer in a cocked position, yielding means urging said sear into its engaging position with said hammer, a trigger slidably mounted in said 6 second housing for longitudinal movement relative to said sear, resilient means urging s aid trigger forwardly to an inoperative position, and a disconnector on said trigger engageable with said sear during rearward movement of said trigger to pivot said Sear out of engagement with said hammer.

ALONZO F. GAIDOS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 898,038 Clarus Sept. 8, 1908 915,087 Flyberg Mar. 16, 1909 930,305 Maudry Aug. 3, 1909 950,576 Paulson Mar. 1, 1910 976,122 Clement Nov. 15, 1910 1,972,763 Dutton Sept. 4, 1934 2,117,218 Sanders May 10, 1938 2,356,615 Revelli Aug. 22, 1944 

